Variabilidade de Botrytis cinerea de roseiras e detecção da mutação associadas à resistência a fungicidas pelo método de dissociação de alta resolução

• Ano de defesa: 2013
• Autor(a) principal: Pérez, Ana Elisa Silvera
• Orientador(a): Maffia, Luiz Antônio
• Banca de defesa: Pinto, Cleide Maria Ferreira , Sanhueza, Rosa Maria Valdebenito
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitopatologia
• Departamento: Etiologia; Epidemiologia; Controle
• País: BR
• Palavras-chave em Português: Mofo Cinzento; HRM; Ligh resolution melting; Epidemiologia; Variabilidade
• Palavras-chave em Inglês: Moho gris; HRM; Ligh resolution melting; Epidemiology; Variability
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1059

Botrytis cinerea is widely distributed throughout the world and causes the gray mold in several crops. In roses, the disease management is based on intensive application of fungicides. This application is not always effective, given the high variability of B. cinerea, particularly regarding sensitivity to fungicides. In Brazil, studies on the variability of the pathogen are demanded. Therefore we aimed at characterizing isolates of B. cinerea gotten from roses grown in greenhouses located in Barbacena - MG, in 2011 and 2012, and in Holambra - SP, in 2011, regarding aggressiveness on rose petals and sensitivity to fungicides. We obtained 308 isolates, which differed in aggressiveness. Considering the sensitivity to fungicides, the isolates were resistant to methyl thiophanate and varied from sensitive to resistant to iprodione (0.1 < EC50 < 4&#956;g.mL-1) and boscalid (0.001 < EC50 < 1000&#956;g.mL-1). There was no correlation between the components of aggressiveness and the resistance to the fungicides. The population was not structured by region regarding the variables analyzed. High variability in aggressiveness and sensitivity to fungicides highlight the problem of chemical control of gray mold. We also attempted to characterize the mutation associated with resistance to fungicides and to detect it by the "highresolution melting" (HRM) analysis in isolates collected in Barbacena in 2012. In the partial sequences of genes analyzed, mutations were detected in BenA (E198A), BcOS1 (I365S/N, Q369P, N373S) and SdhB (H272Y/R) genes associated with resistance to methyl thiophanate, iprodione and boscalid, respectively. The results of HRM and analysis of sequences of BenA, BcOS1 and SdhB were concordant. It is considered that the HRM is a potential tool for monitoring, in the field, the resistance of B. cinerea to fungicides.